I have a new laptop (Lenovo Legion 7, Win10 install) which I've been using for about a week now. However, with watching videos (Youtube mainly) & streams (Twitch) I get stuttering video playback. The laptop has a NVidia RTX 2070 Max-Q graphics chip so I wouldn't think that is the issue. I've seen several different topics on the internet already about tweaking settings in the about:config page related to video stuttering (though most relate to clearing media.benchmark.vp9.fps and restarting FF). None of those things helped. The only thing I found was disabling hardware acceleration. If I disable that, everything is fine with both video & stream playback. I wonder if this is related to the NVidia driver, but I have the latest one installed on the system (457.51 as of writing). This issue also persisted with older drivers that came with the system.

The attached data is from when I have the hardware acceleration enabled, and thus have the stuttering video playback.